Conventional supports are known for mounting fixtures to ceilings during new construction, and as retrofit installations in existing structures.
Nowadays, not only are fixtures, such as chandeliers and ceiling fans, becoming even heavier than prior art fixtures, but building codes are becoming more strict. Thus, there is a need for a fixture mounting assembly which can carry relatively high static and dynamic loads.
There is likewise a need for a fixture mounting assembly which can be used for new construction as well as for retrofit installations, is easy to operate, stronger, and more stable than existing devices.
An example of existing technology is shown in my earlier U.S. Pat. No. 4,463,923 to Reiker which discloses an expandable junction box/fixture hanger assembly for heavy duty applications. Although that hanger assembly works well, there is a need for a fixture mounting assembly which is even simpler to fabricate and easier to use, while meeting the requirements of supporting heavy and/or vibrating fixtures.
U.S. Pat. No. 3,214,126 to Roos is of interest for its disclosure of an outlet box support having mating telescoping bar members 12, 14 comprising a hanger bar. The Roos sidewalls of bar member 12 have interned flanges or lips which project inwardly and are spaced from and parallel to the Roos connecting wall. Roos states that the bar members are identical except as to differences in size. Roos discloses mounting/clamping together an electrical box to the hanger bar by use of a mounting device. The Roos mounting device is considered to be relatively complicated.
U.S. Pat. No. 3,518,421 to Cogdill for a hanger structure discloses telescoping members mountable to an electrical junction box, analogous to the above-described Roos outlet box support.
U.S. Pat. No. 2,528,418 to Buckels discloses telescoping mounting members and mounting flanges having holes therein. Fasteners, such as nails or screws, are inserted through the holes in the mounting flanges for securing the Buckels device to a joist, for example. Buckels expects the depth of the mounting flanges to be substantially equal to the depth of the attached outlet box minus the thickness of the wall construction formed on the joists. Thus, Buckels expects the device to be properly located with respect to the surface of a finished wall surrounding the electrical box.
U.S. Pat. No. 2,945,661 to Appleton discloses a telescoping bar hanger assembly having mounting flanges which are mountable to a joist by hammering nails through openings provided thereon. Appleton suggests that sharp lanced or struck-out deformations having outwardly extending teeth be provided around the nail holes for facilitating the mounting of the bar hanger between joists.